<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .div1 {
            width: 200px;
            height: 80px;
            background-color: red;
            transition: width 4s;
        }
        
        .div1:hover {
            width: 400px;
            cursor: pointer;
        }
        
        .div2 {
            width: 200px;
            height: 80px;
            background-color: blueviolet;
            transition: width 4s;
        }
        
        .div2:hover {
            width: 400px;
            cursor: pointer;
        }
        
        .div3 {
            width: 200px;
            height: 80px;
            background-color: gray;
            transition: width 4s;
        }
        
        .div3:hover {
            width: 400px;
            cursor: pointer;
        }
    </style>
</head>

<body>
    <div class="div1">

    </div>
    <div class="div2">

    </div>
    <div class="div3">

    </div>
</body>

</html>